This invention relates to a radiator cooling apparatus for an internal combustion engine, especially for an automotive engine, equipped with a water circulating radiator system.
In a conventional radiator cooling system, a fan is attached to a fan hub of the engine by means of bolts, and is driven by the engine. A powerful airflow is produced by the fan, and the airflow passes through the core of the radiator, along the direction from the fan to the core or from the core to the fan depending upon the type of the fan. Therefore, the fan itself is indispensable to the radiator cooling system.
Since the conventional fan is open to the atmosphere, great noise is emitted around the fan. This noise constitutes the greatest part of the engine noise.
Around the periphery of a fan, a fan shroud is usually mounted in order to guide and promote the airflow produced by the fan. From a view point of reducing the fan noise, the fan shroud is not very effective.
Japanese utility model public disclosure No. 158150/1979 discloses a soundproof cover isolating the engine from the atmosphere. A cooling fan for the engine is disposed outside of the cover and is driven by an electrical motor. However, this fan is open to the atmosphere and without soundproofing means.
From another point of view, a conventional fan has a disadvantage in that it leads to an enlargement of the total length of the engine, because the fan is situated at the distal end of the engine. In particular, when the engine is mounted on such a car as a so-called front-engine front-drive type, in which the engine is laid laterally to the centerline of the car, the total length of the engine becomes a matter of great concern.